The night that Charles Kennedy admitted he had a drink problem, readers of Nick Robinson's BBC weblog debated the merits of the story. "What this story really shows," said one, "is the degree to which political journalists are drawn in and become complicit in the 'Westminster Bubble'." Another added: "Reporters are not in the business of withholding secrets in some cabal with politicians to keep genuine and valid news from the public." Others disagreed. "The feeding frenzy surrounding Kennedy is horrific," said one. "Here's the truth. He has a medical problem, an illness if you like. He has taken the major steps in addressing that problem - admitted there is one and sought professional help. If he is forced to go, then every MP who drinks too much or who has a significant physical or mental health problem should go too."

It is not surprising that readers, viewers and listeners sometimes wonder whether journalists get a little too close to their subjects. The lobby system has been under attack for years because it is felt by many to be a cosy club dedicated to the interests of its members rather than the public. It is not just the lobby. All specialist correspondents inevitably get close to their subjects and their sources. That is part of the price of being an expert. The balance to be struck is knowing when the time has come to publish the story regardless of the possible damage to relationships. Most politicians would, I suspect, feel that that happens more often than they find comfortable.

But also look at the background to this story. As Robinson pointed out on his blog: "There is a big difference between knowing that Kennedy drank a lot and knowing that he had a drink problem and was undergoing treatment."

The relationship between politicians (and journalists) and the bottle is well known. Fuelling contacts and relationships, loosening tongues, alcohol helps journalists get their story. If someone drinks more than they should, is that something to be reported on a daily basis, or does it only become reportable once it is clear that there is a problem which is having a significant impact on their ability to do the job? And even then, how do you stand the story up and publish while staying within the law of defamation?

Clearly, there had been rumours about Kennedy over a long period but they stayed rumours until the plates shifted under him within his own party. At a BBC lunch last year there was no sign of alcohol dependency, it was nicotine that seemed to be his problem. If there was any collusion it was as much between Kennedy and his close colleagues who, not to put too fine a point on it, lied to protect him. For three years journalists have posed the question in public and in private and have been told there was no problem. There are limits of tact and sensitivity if a story, which at that stage was still largely personal, is denied.

It only became a story in the public interest once it became clear that his colleagues were no longer prepared, for whatever reason, to go on colluding with the poor performance that resulted from his drinking. The rebellion before Christmas was the beginning of the end in keeping the lid on the "problem". Hypocrisy on both sides? Maybe. But leaving aside whether those who have sinned should cast the first stone, on this occasion journalists were caught between a rock and a hard place. They had been criticised for asking Kennedy whether he drank too much and withdrew in the face of his denials. They finally reported it when he himself made a public acknowledgement of his problem.

It is a sad personal story but as Kennedy hopefully makes progress in his fight with alcohol, it would be good to think that another benefit might be some further reflection by the media on what constitutes a story being in the "public interest". It is always the first refuge of every editor seeking to defend a story that verges on intrusion. But what does it comprise?